Annual Plant Reviews, Volume 13 Plastids are essential plant organelles, vital for life on earth. They are important not just as photosynthetic organelles (chloroplasts) but also as sites involved in many fundamental intermediary metabolic pathways. Over the last decade, plastid research has seen tremendous advances and an exciting new picture is emerging of how plastids develop and function inside plant cells. The recent and rapid progress in the field has been due largely to reverse genetic...